I think the message of Howl’s Moving Castle is that in order to maintain a successful relationship with some kind of fucked up wizard, you must find it in yourself to also be some kind of fucked up wizard.
when i was at walgreens (at 3 in the morning which explains all of this) the cashier was talking to her coworker about how shed rather be a werewolf than a vampire because vampires are condemned to hell but werewolves arent and then she asked me what i thought and i said vampire because im already condemned to hell and she said in the nicest tone of voice “i dont think anybody is condemned to hell….” paused, stared at me for a few moments, and added on “…not even gay people”